1. Field of the Disclosure
The present disclosure relates generally to differential receivers and, more particularly, to complementary self-biased differential amplifiers.
2. Description of the Related Art
As electronic devices become more sophisticated and consumers expect increased functionality, small device size, and extended battery life, techniques are utilized to reduce device size and decrease power consumption without sacrificing functionality. One such technique involves operating an electronic device at a low voltage. However, low voltage operation can present obstacles to achieving the desired functionality.
One technique to implement lower voltage operation is to employ differential signaling, whereby a differential receiver is used to receive differential mode signals from other devices. Some differential receivers use self-biased differential amplifiers. However, as operating voltages are reduced conventional self-biased amplifiers suffer from low speed, and can also demand a large circuit area. For example, some self-biased amplifier topologies require stacks of transistors dedicated specifically to providing a self-biasing voltage, and such self-biasing transistor stacks occupy large amounts of area, interfering with the quest for smaller electronic devices. Moreover, limited output swing and intolerance to variations in process, voltage, and temperature (PVT) further hinder use of typical self-biased amplifier topologies. For example, at low supply voltage differences (i.e., low positive supply voltage (Vdd) relative to negative supply voltage), in typical self-biased amplifiers, tail current sources are provided with relatively low bias relative to the threshold voltage (Vth) of the tail current source transistors, which inhibits proper operation of the circuit.
The use of the same reference symbols in different drawings indicates similar or identical items.